1. Field of the Invention
The present invention relates to a method and apparatus for remotely measuring surface air pressure.
2. Description of Related Art
Surface air pressure is one of the most important parameters regularly measured at surface meteorological stations. With development of remote sensing methods, especially in airborne and satellite remote sensing techniques, large-scale and global surface pressure measurements significantly lag behind other important parameters, such as surface temperature. One known technique uses satellite oxygen A-band methods to measure surface air pressure. The aforesaid known oxygen A-band methods are either passive, or rely upon active instruments. The active instruments rely on the operation of complicated highly stable laser systems on a space platform and are thus, technically difficult to implement. On the other hand, the passive methods are restricted to daytime measurements and areas of low cloud cover.
A review of issued U.S. patents reveals several techniques to measure atmospheric air pressure, temperature and moisture. Fema, U.S. Pat. No. 5,111,055 discloses a method and system for the optical measurements of the air pressure by laser excitation, particularly in front of an aircraft. Korb et al., U.S. Pat. No. 4,493,553 discloses a method and apparatus for measuring temperature and pressure that uses a laser beam. Fujisaka et al., U.S. Pat. No. 6,081,220 discloses a radar system for observing weather phenomena. Argento, U.S. Pat. No. 2,703,079 discloses a method of and apparatus for determining the oxygen content of a gas. Shnier, U.S. Pat. No. 6,590,661 discloses optical methods for selectively sensing remote vocal sound waves. Nelson et al., discloses a microwave radiometer and methods for sensing atmospheric moisture and temperature. McCaul et al., U.S. Pat. No. 5,625,189 discloses a technique using gas spectroscopy that entails generating laser radiation, passing the laser radiation through a volume containing human breath multiple times, and detecting the laser radiation that is not absorbed by gases in the volume.
None of these known techniques provide a reliable, accurate, cost effective and active system to remotely sense measurements of surface air pressure.